While I am sure the code snippets look great in glorious color, the gray tones used in the printed paperback are hard to read for method calls and screaming-snake-cased constants.
Please print in color or improve the contrast in some other way. A boomer thanks you.
I see mjk has the same issue as me. No doubt everyone else has the same issue: the code is unreadable!
But this is not something you should bring up with an editor – someday. This is something you should bring up with management RIGHT NOW, because someone made a decision that makes YOUR BOOK largely unreadable. The code is in black and medium gray on slightly lighter medium gray. WTF? A company called PRAGMATIC PROGRAMMING sent a book to the printer without anyone ever looking at it? Not very pragmatic.